4 * Holds LTTng per-session event registry.
6 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include <urcu/list.h>
26 #include <urcu/hlist.h>
35 #include <lttng/ust-endian.h>
39 #include <urcu/compiler.h>
40 #include <urcu/uatomic.h>
41 #include <urcu/arch.h>
43 #include <lttng/tracepoint.h>
44 #include <lttng/ust-events.h>
46 #include <usterr-signal-safe.h>
50 #include "lttng-ust-uuid.h"
52 #include "tracepoint-internal.h"
53 #include "lttng-tracer.h"
54 #include "lttng-tracer-core.h"
56 #include "../libringbuffer/shm.h"
60 * The sessions mutex is the centralized mutex across UST tracing
61 * control and probe registration. All operations within this file are
62 * called by the communication thread, under ust_lock protection.
64 static pthread_mutex_t sessions_mutex
= PTHREAD_MUTEX_INITIALIZER
;
68 pthread_mutex_lock(&sessions_mutex
);
73 pthread_mutex_unlock(&sessions_mutex
);
76 static CDS_LIST_HEAD(sessions
);
78 static void _lttng_event_destroy(struct lttng_event
*event
);
79 static void _lttng_channel_destroy(struct lttng_channel
*chan
);
80 static int _lttng_event_unregister(struct lttng_event
*event
);
82 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
83 struct lttng_channel
*chan
,
84 struct lttng_event
*event
);
86 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
89 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
);
91 void lttng_session_sync_enablers(struct lttng_session
*session
);
93 void lttng_enabler_destroy(struct lttng_enabler
*enabler
);
96 int lttng_loglevel_match(int loglevel
,
97 unsigned int has_loglevel
,
98 enum lttng_ust_loglevel_type req_type
,
101 if (req_type
== LTTNG_UST_LOGLEVEL_ALL
)
104 loglevel
= TRACE_DEFAULT
;
106 case LTTNG_UST_LOGLEVEL_RANGE
:
107 if (loglevel
<= req_loglevel
|| req_loglevel
== -1)
111 case LTTNG_UST_LOGLEVEL_SINGLE
:
112 if (loglevel
== req_loglevel
|| req_loglevel
== -1)
116 case LTTNG_UST_LOGLEVEL_ALL
:
122 void synchronize_trace(void)
127 struct lttng_session
*lttng_session_create(void)
129 struct lttng_session
*session
;
132 session
= zmalloc(sizeof(struct lttng_session
));
135 CDS_INIT_LIST_HEAD(&session
->chan_head
);
136 CDS_INIT_LIST_HEAD(&session
->events_head
);
137 CDS_INIT_LIST_HEAD(&session
->enablers_head
);
138 ret
= lttng_ust_uuid_generate(session
->uuid
);
140 session
->uuid
[0] = '\0';
142 cds_list_add(&session
->node
, &sessions
);
146 void lttng_session_destroy(struct lttng_session
*session
)
148 struct lttng_channel
*chan
, *tmpchan
;
149 struct lttng_event
*event
, *tmpevent
;
150 struct lttng_enabler
*enabler
, *tmpenabler
;
153 CMM_ACCESS_ONCE(session
->active
) = 0;
154 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
155 ret
= _lttng_event_unregister(event
);
158 synchronize_trace(); /* Wait for in-flight events to complete */
159 cds_list_for_each_entry_safe(enabler
, tmpenabler
,
160 &session
->enablers_head
, node
)
161 lttng_enabler_destroy(enabler
);
162 cds_list_for_each_entry_safe(event
, tmpevent
,
163 &session
->events_head
, node
)
164 _lttng_event_destroy(event
);
165 cds_list_for_each_entry_safe(chan
, tmpchan
, &session
->chan_head
, node
)
166 _lttng_channel_destroy(chan
);
167 cds_list_del(&session
->node
);
171 int lttng_session_enable(struct lttng_session
*session
)
174 struct lttng_channel
*chan
;
176 if (session
->active
) {
181 /* We need to sync enablers with session before activation. */
182 lttng_session_sync_enablers(session
);
185 * Snapshot the number of events per channel to know the type of header
188 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
189 if (chan
->header_type
)
190 continue; /* don't change it if session stop/restart */
191 if (chan
->free_event_id
< 31)
192 chan
->header_type
= 1; /* compact */
194 chan
->header_type
= 2; /* large */
197 CMM_ACCESS_ONCE(session
->active
) = 1;
198 CMM_ACCESS_ONCE(session
->been_active
) = 1;
199 ret
= _lttng_session_metadata_statedump(session
);
201 CMM_ACCESS_ONCE(session
->active
) = 0;
206 int lttng_session_disable(struct lttng_session
*session
)
210 if (!session
->active
) {
214 CMM_ACCESS_ONCE(session
->active
) = 0;
219 int lttng_channel_enable(struct lttng_channel
*channel
)
223 if (channel
== channel
->session
->metadata
)
225 old
= uatomic_xchg(&channel
->enabled
, 1);
231 int lttng_channel_disable(struct lttng_channel
*channel
)
235 if (channel
== channel
->session
->metadata
)
237 old
= uatomic_xchg(&channel
->enabled
, 0);
243 int lttng_event_enable(struct lttng_event
*event
)
247 if (event
->chan
== event
->chan
->session
->metadata
)
249 old
= uatomic_xchg(&event
->enabled
, 1);
255 int lttng_event_disable(struct lttng_event
*event
)
259 if (event
->chan
== event
->chan
->session
->metadata
)
261 old
= uatomic_xchg(&event
->enabled
, 0);
267 struct lttng_channel
*lttng_channel_create(struct lttng_session
*session
,
268 const char *transport_name
,
270 size_t subbuf_size
, size_t num_subbuf
,
271 unsigned int switch_timer_interval
,
272 unsigned int read_timer_interval
,
273 int **shm_fd
, int **wait_fd
,
274 uint64_t **memory_map_size
,
275 struct lttng_channel
*chan_priv_init
)
277 struct lttng_channel
*chan
= NULL
;
278 struct lttng_transport
*transport
;
280 if (session
->been_active
)
281 goto active
; /* Refuse to add channel to active session */
282 transport
= lttng_transport_find(transport_name
);
284 DBG("LTTng transport %s not found\n",
288 chan_priv_init
->id
= session
->free_chan_id
++;
289 chan_priv_init
->session
= session
;
291 * Note: the channel creation op already writes into the packet
292 * headers. Therefore the "chan" information used as input
293 * should be already accessible.
295 chan
= transport
->ops
.channel_create(transport_name
, buf_addr
,
296 subbuf_size
, num_subbuf
, switch_timer_interval
,
297 read_timer_interval
, shm_fd
, wait_fd
,
298 memory_map_size
, chan_priv_init
);
302 chan
->ops
= &transport
->ops
;
303 cds_list_add(&chan
->node
, &session
->chan_head
);
313 * Only used internally at session destruction.
316 void _lttng_channel_destroy(struct lttng_channel
*chan
)
318 cds_list_del(&chan
->node
);
319 lttng_destroy_context(chan
->ctx
);
320 chan
->ops
->channel_destroy(chan
);
324 * Supports event creation while tracing session is active.
327 int lttng_event_create(const struct lttng_event_desc
*desc
,
328 struct lttng_channel
*chan
)
330 const char *event_name
= desc
->name
;
331 struct lttng_event
*event
;
334 if (chan
->used_event_id
== -1U) {
339 * This is O(n^2) (for each event, the loop is called at event
340 * creation). Might require a hash if we have lots of events.
342 cds_list_for_each_entry(event
, &chan
->session
->events_head
, node
) {
344 if (!strncmp(event
->desc
->name
,
346 LTTNG_UST_SYM_NAME_LEN
- 1)) {
353 * Check if loglevel match. Refuse to connect event if not.
355 event
= zmalloc(sizeof(struct lttng_event
));
363 * used_event_id counts the maximum number of event IDs that can
364 * register if all probes register.
366 chan
->used_event_id
++;
368 CDS_INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
369 CDS_INIT_LIST_HEAD(&event
->enablers_ref_head
);
371 /* Populate lttng_event structure before tracepoint registration. */
373 ret
= __tracepoint_probe_register(event_name
,
374 desc
->probe_callback
,
375 event
, desc
->signature
);
378 event
->id
= chan
->free_event_id
++;
379 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
381 goto statedump_error
;
382 cds_list_add(&event
->node
, &chan
->session
->events_head
);
386 WARN_ON_ONCE(__tracepoint_probe_unregister(event_name
,
387 desc
->probe_callback
,
389 lttng_event_put(event
->desc
);
399 int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc
*desc
,
400 struct lttng_enabler
*enabler
)
403 unsigned int has_loglevel
;
405 assert(enabler
->type
== LTTNG_ENABLER_WILDCARD
);
406 /* Compare excluding final '*' */
407 if (strncmp(desc
->name
, enabler
->event_param
.name
,
408 strlen(enabler
->event_param
.name
) - 1))
410 if (desc
->loglevel
) {
411 loglevel
= *(*desc
->loglevel
);
414 if (!lttng_loglevel_match(loglevel
,
416 enabler
->event_param
.loglevel_type
,
417 enabler
->event_param
.loglevel
))
423 int lttng_desc_match_event_enabler(const struct lttng_event_desc
*desc
,
424 struct lttng_enabler
*enabler
)
427 unsigned int has_loglevel
= 0;
429 assert(enabler
->type
== LTTNG_ENABLER_EVENT
);
430 if (strcmp(desc
->name
, enabler
->event_param
.name
))
432 if (desc
->loglevel
) {
433 loglevel
= *(*desc
->loglevel
);
436 if (!lttng_loglevel_match(loglevel
,
438 enabler
->event_param
.loglevel_type
,
439 enabler
->event_param
.loglevel
))
445 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
446 struct lttng_enabler
*enabler
)
448 switch (enabler
->type
) {
449 case LTTNG_ENABLER_WILDCARD
:
450 return lttng_desc_match_wildcard_enabler(desc
, enabler
);
451 case LTTNG_ENABLER_EVENT
:
452 return lttng_desc_match_event_enabler(desc
, enabler
);
459 int lttng_event_match_enabler(struct lttng_event
*event
,
460 struct lttng_enabler
*enabler
)
462 return lttng_desc_match_enabler(event
->desc
, enabler
);
466 struct lttng_enabler_ref
* lttng_event_enabler_ref(struct lttng_event
*event
,
467 struct lttng_enabler
*enabler
)
469 struct lttng_enabler_ref
*enabler_ref
;
471 cds_list_for_each_entry(enabler_ref
,
472 &event
->enablers_ref_head
, node
) {
473 if (enabler_ref
->ref
== enabler
)
480 * Create struct lttng_event if it is missing and present in the list of
484 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
486 struct lttng_session
*session
= enabler
->chan
->session
;
487 struct lttng_probe_desc
*probe_desc
;
488 const struct lttng_event_desc
*desc
;
489 struct lttng_event
*event
;
491 struct cds_list_head
*probe_list
;
493 probe_list
= lttng_get_probe_list_head();
495 * For each probe event, if we find that a probe event matches
496 * our enabler, create an associated lttng_event if not
499 cds_list_for_each_entry(probe_desc
, probe_list
, head
) {
500 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
503 desc
= probe_desc
->event_desc
[i
];
504 if (!lttng_desc_match_enabler(desc
, enabler
))
508 * For each event in session event list,
509 * check if already created.
511 cds_list_for_each_entry(event
,
512 &session
->events_head
, node
) {
513 if (event
->desc
== desc
)
520 * We need to create an event for this
523 ret
= lttng_event_create(probe_desc
->event_desc
[i
],
526 DBG("Unable to create event %s\n",
527 probe_desc
->event_desc
[i
]->name
);
534 * Create events associated with an enabler (if not already present),
535 * and add backward reference from the event to the enabler.
538 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
540 struct lttng_session
*session
= enabler
->chan
->session
;
541 struct lttng_event
*event
;
543 /* First ensure that probe events are created for this enabler. */
544 lttng_create_event_if_missing(enabler
);
546 /* For each event matching enabler in session event list. */
547 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
548 struct lttng_enabler_ref
*enabler_ref
;
550 if (!lttng_event_match_enabler(event
, enabler
))
553 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
556 * If no backward ref, create it.
557 * Add backward ref from event to enabler.
559 enabler_ref
= zmalloc(sizeof(*enabler_ref
));
562 enabler_ref
->ref
= enabler
;
563 cds_list_add(&enabler_ref
->node
,
564 &event
->enablers_ref_head
);
568 * Link filter bytecodes if not linked yet.
570 lttng_enabler_event_link_bytecode(event
, enabler
);
572 /* TODO: merge event context. */
578 * Called at library load: connect the probe on all enablers matching
580 * called with session mutex held.
581 * TODO: currently, for each desc added, we iterate on all event desc
582 * (inefficient). We should create specific code that only target the
585 int lttng_fix_pending_event_desc(const struct lttng_event_desc
*desc
)
587 struct lttng_session
*session
;
589 cds_list_for_each_entry(session
, &sessions
, node
) {
590 lttng_session_lazy_sync_enablers(session
);
596 * Only used internally at session destruction.
598 int _lttng_event_unregister(struct lttng_event
*event
)
600 return __tracepoint_probe_unregister(event
->desc
->name
,
601 event
->desc
->probe_callback
,
606 * Only used internally at session destruction.
609 void _lttng_event_destroy(struct lttng_event
*event
)
611 struct lttng_enabler_ref
*enabler_ref
, *tmp_enabler_ref
;
613 lttng_event_put(event
->desc
);
614 cds_list_del(&event
->node
);
615 lttng_destroy_context(event
->ctx
);
616 lttng_free_event_filter_runtime(event
);
617 /* Free event enabler refs */
618 cds_list_for_each_entry_safe(enabler_ref
, tmp_enabler_ref
,
619 &event
->enablers_ref_head
, node
)
625 * We have exclusive access to our metadata buffer (protected by the
626 * ust_lock), so we can do racy operations such as looking for
627 * remaining space left in packet and write, since mutual exclusion
628 * protects us from concurrent writes.
630 int lttng_metadata_printf(struct lttng_session
*session
,
631 const char *fmt
, ...)
633 struct lttng_ust_lib_ring_buffer_ctx ctx
;
634 struct lttng_channel
*chan
= session
->metadata
;
636 int ret
= 0, waitret
;
637 size_t len
, reserve_len
, pos
;
640 WARN_ON_ONCE(!CMM_ACCESS_ONCE(session
->active
));
643 ret
= vasprintf(&str
, fmt
, ap
);
651 for (pos
= 0; pos
< len
; pos
+= reserve_len
) {
652 reserve_len
= min_t(size_t,
653 chan
->ops
->packet_avail_size(chan
->chan
, chan
->handle
),
655 lib_ring_buffer_ctx_init(&ctx
, chan
->chan
, NULL
, reserve_len
,
656 sizeof(char), -1, chan
->handle
);
658 * We don't care about metadata buffer's records lost
659 * count, because we always retry here. Report error if
660 * we need to bail out after timeout or being
663 waitret
= wait_cond_interruptible_timeout(
665 ret
= chan
->ops
->event_reserve(&ctx
, 0);
666 ret
!= -ENOBUFS
|| !ret
;
668 LTTNG_METADATA_TIMEOUT_MSEC
);
669 if (waitret
== -ETIMEDOUT
|| waitret
== -EINTR
|| ret
) {
670 DBG("LTTng: Failure to write metadata to buffers (%s)\n",
671 waitret
== -EINTR
? "interrupted" :
672 (ret
== -ENOBUFS
? "timeout" : "I/O error"));
673 if (waitret
== -EINTR
)
677 chan
->ops
->event_write(&ctx
, &str
[pos
], reserve_len
);
678 chan
->ops
->event_commit(&ctx
);
686 int _lttng_field_statedump(struct lttng_session
*session
,
687 const struct lttng_event_field
*field
)
694 switch (field
->type
.atype
) {
696 ret
= lttng_metadata_printf(session
,
697 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
698 field
->type
.u
.basic
.integer
.size
,
699 field
->type
.u
.basic
.integer
.alignment
,
700 field
->type
.u
.basic
.integer
.signedness
,
701 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
703 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
706 field
->type
.u
.basic
.integer
.base
,
707 #if (BYTE_ORDER == BIG_ENDIAN)
708 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
710 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
715 ret
= lttng_metadata_printf(session
,
716 " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
717 field
->type
.u
.basic
._float
.exp_dig
,
718 field
->type
.u
.basic
._float
.mant_dig
,
719 field
->type
.u
.basic
._float
.alignment
,
720 #if (BYTE_ORDER == BIG_ENDIAN)
721 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
723 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
728 ret
= lttng_metadata_printf(session
,
730 field
->type
.u
.basic
.enumeration
.name
,
735 const struct lttng_basic_type
*elem_type
;
737 elem_type
= &field
->type
.u
.array
.elem_type
;
738 ret
= lttng_metadata_printf(session
,
739 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
740 elem_type
->u
.basic
.integer
.size
,
741 elem_type
->u
.basic
.integer
.alignment
,
742 elem_type
->u
.basic
.integer
.signedness
,
743 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
745 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
748 elem_type
->u
.basic
.integer
.base
,
749 #if (BYTE_ORDER == BIG_ENDIAN)
750 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
752 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
754 field
->name
, field
->type
.u
.array
.length
);
759 const struct lttng_basic_type
*elem_type
;
760 const struct lttng_basic_type
*length_type
;
762 elem_type
= &field
->type
.u
.sequence
.elem_type
;
763 length_type
= &field
->type
.u
.sequence
.length_type
;
764 ret
= lttng_metadata_printf(session
,
765 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
766 length_type
->u
.basic
.integer
.size
,
767 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
768 length_type
->u
.basic
.integer
.signedness
,
769 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
771 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
774 length_type
->u
.basic
.integer
.base
,
775 #if (BYTE_ORDER == BIG_ENDIAN)
776 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
778 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
784 ret
= lttng_metadata_printf(session
,
785 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
786 elem_type
->u
.basic
.integer
.size
,
787 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
788 elem_type
->u
.basic
.integer
.signedness
,
789 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
791 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
794 elem_type
->u
.basic
.integer
.base
,
795 #if (BYTE_ORDER == BIG_ENDIAN)
796 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
798 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
806 /* Default encoding is UTF8 */
807 ret
= lttng_metadata_printf(session
,
809 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
810 " { encoding = ASCII; }" : "",
821 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
822 struct lttng_ctx
*ctx
)
829 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
830 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
832 ret
= _lttng_field_statedump(session
, &field
->event_field
);
840 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
841 struct lttng_event
*event
)
843 const struct lttng_event_desc
*desc
= event
->desc
;
847 for (i
= 0; i
< desc
->nr_fields
; i
++) {
848 const struct lttng_event_field
*field
= &desc
->fields
[i
];
850 ret
= _lttng_field_statedump(session
, field
);
858 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
859 struct lttng_channel
*chan
,
860 struct lttng_event
*event
)
863 int loglevel
= TRACE_DEFAULT
;
865 if (event
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
867 if (chan
== session
->metadata
)
870 * Don't print events for which probe load is pending.
875 ret
= lttng_metadata_printf(session
,
879 " stream_id = %u;\n",
886 if (event
->desc
->loglevel
)
887 loglevel
= *(*event
->desc
->loglevel
);
889 ret
= lttng_metadata_printf(session
,
895 if (event
->desc
->u
.ext
.model_emf_uri
) {
896 ret
= lttng_metadata_printf(session
,
897 " model.emf.uri = \"%s\";\n",
898 *(event
->desc
->u
.ext
.model_emf_uri
));
904 ret
= lttng_metadata_printf(session
,
905 " context := struct {\n");
909 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
913 ret
= lttng_metadata_printf(session
,
919 ret
= lttng_metadata_printf(session
,
920 " fields := struct {\n"
925 ret
= _lttng_fields_metadata_statedump(session
, event
);
930 * LTTng space reservation can only reserve multiples of the
933 ret
= lttng_metadata_printf(session
,
939 event
->metadata_dumped
= 1;
946 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
947 struct lttng_channel
*chan
)
951 if (chan
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
953 if (chan
== session
->metadata
)
956 WARN_ON_ONCE(!chan
->header_type
);
957 ret
= lttng_metadata_printf(session
,
960 " event.header := %s;\n"
961 " packet.context := struct packet_context;\n",
963 chan
->header_type
== 1 ? "struct event_header_compact" :
964 "struct event_header_large");
969 ret
= lttng_metadata_printf(session
,
970 " event.context := struct {\n");
974 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
978 ret
= lttng_metadata_printf(session
,
984 ret
= lttng_metadata_printf(session
,
987 chan
->metadata_dumped
= 1;
993 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
995 return lttng_metadata_printf(session
,
996 "struct packet_context {\n"
997 " uint64_clock_monotonic_t timestamp_begin;\n"
998 " uint64_clock_monotonic_t timestamp_end;\n"
999 " uint64_t content_size;\n"
1000 " uint64_t packet_size;\n"
1001 " unsigned long events_discarded;\n"
1002 " uint32_t cpu_id;\n"
1009 * id: range: 0 - 30.
1010 * id 31 is reserved to indicate an extended header.
1013 * id: range: 0 - 65534.
1014 * id 65535 is reserved to indicate an extended header.
1017 int _lttng_event_header_declare(struct lttng_session
*session
)
1019 return lttng_metadata_printf(session
,
1020 "struct event_header_compact {\n"
1021 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1024 " uint27_clock_monotonic_t timestamp;\n"
1028 " uint64_clock_monotonic_t timestamp;\n"
1033 "struct event_header_large {\n"
1034 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1037 " uint32_clock_monotonic_t timestamp;\n"
1041 " uint64_clock_monotonic_t timestamp;\n"
1045 lttng_alignof(uint32_t) * CHAR_BIT
,
1046 lttng_alignof(uint16_t) * CHAR_BIT
1051 * Approximation of NTP time of day to clock monotonic correlation,
1052 * taken at start of trace.
1053 * Yes, this is only an approximation. Yes, we can (and will) do better
1054 * in future versions.
1057 uint64_t measure_clock_offset(void)
1059 uint64_t offset
, monotonic
[2], realtime
;
1060 struct timespec rts
= { 0, 0 };
1063 monotonic
[0] = trace_clock_read64();
1064 ret
= clock_gettime(CLOCK_REALTIME
, &rts
);
1067 monotonic
[1] = trace_clock_read64();
1068 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
1069 realtime
= (uint64_t) rts
.tv_sec
* 1000000000ULL;
1070 realtime
+= rts
.tv_nsec
;
1071 offset
= realtime
- offset
;
1076 * Output metadata into this session's metadata buffers.
1079 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
1081 unsigned char *uuid_c
= session
->uuid
;
1082 char uuid_s
[LTTNG_UST_UUID_STR_LEN
],
1083 clock_uuid_s
[LTTNG_UST_UUID_STR_LEN
];
1084 struct lttng_channel
*chan
;
1085 struct lttng_event
*event
;
1087 char procname
[LTTNG_UST_PROCNAME_LEN
] = "";
1088 char hostname
[HOST_NAME_MAX
];
1090 if (!CMM_ACCESS_ONCE(session
->active
))
1092 if (session
->metadata_dumped
)
1094 if (!session
->metadata
) {
1095 DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
1099 snprintf(uuid_s
, sizeof(uuid_s
),
1100 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1101 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1102 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1103 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1104 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1106 ret
= lttng_metadata_printf(session
,
1107 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1108 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1109 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1110 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1111 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
1112 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1113 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1119 " byte_order = %s;\n"
1120 " packet.header := struct {\n"
1121 " uint32_t magic;\n"
1122 " uint8_t uuid[16];\n"
1123 " uint32_t stream_id;\n"
1126 lttng_alignof(uint8_t) * CHAR_BIT
,
1127 lttng_alignof(uint16_t) * CHAR_BIT
,
1128 lttng_alignof(uint32_t) * CHAR_BIT
,
1129 lttng_alignof(uint64_t) * CHAR_BIT
,
1130 sizeof(unsigned long) * CHAR_BIT
,
1131 lttng_alignof(unsigned long) * CHAR_BIT
,
1135 #if (BYTE_ORDER == BIG_ENDIAN)
1144 /* ignore error, just use empty string if error. */
1146 ret
= gethostname(hostname
, sizeof(hostname
));
1147 if (ret
&& errno
== ENAMETOOLONG
)
1148 hostname
[HOST_NAME_MAX
- 1] = '\0';
1149 lttng_ust_getprocname(procname
);
1150 procname
[LTTNG_UST_PROCNAME_LEN
- 1] = '\0';
1151 ret
= lttng_metadata_printf(session
,
1153 " hostname = \"%s\";\n"
1155 " procname = \"%s\";\n"
1156 " domain = \"ust\";\n"
1157 " tracer_name = \"lttng-ust\";\n"
1158 " tracer_major = %u;\n"
1159 " tracer_minor = %u;\n"
1160 " tracer_patchlevel = %u;\n"
1165 LTTNG_UST_MAJOR_VERSION
,
1166 LTTNG_UST_MINOR_VERSION
,
1167 LTTNG_UST_PATCHLEVEL_VERSION
1172 ret
= lttng_metadata_printf(session
,
1180 if (!trace_clock_uuid(clock_uuid_s
)) {
1181 ret
= lttng_metadata_printf(session
,
1182 " uuid = \"%s\";\n",
1189 ret
= lttng_metadata_printf(session
,
1190 " description = \"Monotonic Clock\";\n"
1191 " freq = %" PRIu64
"; /* Frequency, in Hz */\n"
1192 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
1193 " offset = %" PRIu64
";\n"
1196 measure_clock_offset()
1201 ret
= lttng_metadata_printf(session
,
1202 "typealias integer {\n"
1203 " size = 27; align = 1; signed = false;\n"
1204 " map = clock.monotonic.value;\n"
1205 "} := uint27_clock_monotonic_t;\n"
1207 "typealias integer {\n"
1208 " size = 32; align = %u; signed = false;\n"
1209 " map = clock.monotonic.value;\n"
1210 "} := uint32_clock_monotonic_t;\n"
1212 "typealias integer {\n"
1213 " size = 64; align = %u; signed = false;\n"
1214 " map = clock.monotonic.value;\n"
1215 "} := uint64_clock_monotonic_t;\n\n",
1216 lttng_alignof(uint32_t) * CHAR_BIT
,
1217 lttng_alignof(uint64_t) * CHAR_BIT
1222 ret
= _lttng_stream_packet_context_declare(session
);
1226 ret
= _lttng_event_header_declare(session
);
1231 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
1232 ret
= _lttng_channel_metadata_statedump(session
, chan
);
1237 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
1238 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
1242 session
->metadata_dumped
= 1;
1247 void lttng_ust_events_exit(void)
1249 struct lttng_session
*session
, *tmpsession
;
1251 cds_list_for_each_entry_safe(session
, tmpsession
, &sessions
, node
)
1252 lttng_session_destroy(session
);
1256 * Enabler management.
1258 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
1259 struct lttng_ust_event
*event_param
,
1260 struct lttng_channel
*chan
)
1262 struct lttng_enabler
*enabler
;
1264 enabler
= zmalloc(sizeof(*enabler
));
1267 enabler
->type
= type
;
1268 CDS_INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
1269 memcpy(&enabler
->event_param
, event_param
,
1270 sizeof(enabler
->event_param
));
1271 enabler
->chan
= chan
;
1273 enabler
->enabled
= 1;
1274 cds_list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
1275 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1279 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
1281 enabler
->enabled
= 1;
1282 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1286 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
1288 if (enabler
->chan
== enabler
->chan
->session
->metadata
)
1290 enabler
->enabled
= 0;
1291 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1295 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
1296 struct lttng_ust_filter_bytecode_node
*bytecode
)
1298 bytecode
->enabler
= enabler
;
1299 cds_list_add_tail(&bytecode
->node
, &enabler
->filter_bytecode_head
);
1300 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1304 int lttng_attach_context(struct lttng_ust_context
*context_param
,
1305 struct lttng_ctx
**ctx
, struct lttng_session
*session
)
1308 * We cannot attach a context after trace has been started for a
1309 * session because the metadata does not allow expressing this
1310 * information outside of the original channel scope.
1312 if (session
->been_active
)
1315 switch (context_param
->ctx
) {
1316 case LTTNG_UST_CONTEXT_PTHREAD_ID
:
1317 return lttng_add_pthread_id_to_ctx(ctx
);
1318 case LTTNG_UST_CONTEXT_VTID
:
1319 return lttng_add_vtid_to_ctx(ctx
);
1320 case LTTNG_UST_CONTEXT_VPID
:
1321 return lttng_add_vpid_to_ctx(ctx
);
1322 case LTTNG_UST_CONTEXT_PROCNAME
:
1323 return lttng_add_procname_to_ctx(ctx
);
1329 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
1330 struct lttng_ust_context
*context_param
)
1332 #if 0 // disabled for now.
1333 struct lttng_session
*session
= enabler
->chan
->session
;
1336 ret
= lttng_attach_context(context_param
, &enabler
->ctx
,
1340 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1346 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1348 struct lttng_ust_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
1350 /* Destroy filter bytecode */
1351 cds_list_for_each_entry_safe(filter_node
, tmp_filter_node
,
1352 &enabler
->filter_bytecode_head
, node
) {
1356 /* Destroy contexts */
1357 lttng_destroy_context(enabler
->ctx
);
1359 cds_list_del(&enabler
->node
);
1364 * lttng_session_sync_enablers should be called just before starting a
1368 void lttng_session_sync_enablers(struct lttng_session
*session
)
1370 struct lttng_enabler
*enabler
;
1371 struct lttng_event
*event
;
1373 cds_list_for_each_entry(enabler
, &session
->enablers_head
, node
)
1374 lttng_enabler_ref_events(enabler
);
1376 * For each event, if at least one of its enablers is enabled,
1377 * we enable the event, else we disable it.
1379 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
1380 struct lttng_enabler_ref
*enabler_ref
;
1381 struct lttng_bytecode_runtime
*runtime
;
1382 int enabled
= 0, has_enablers_without_bytecode
= 0;
1385 cds_list_for_each_entry(enabler_ref
,
1386 &event
->enablers_ref_head
, node
) {
1387 if (enabler_ref
->ref
->enabled
) {
1392 event
->enabled
= enabled
;
1394 /* Check if has enablers without bytecode enabled */
1395 cds_list_for_each_entry(enabler_ref
,
1396 &event
->enablers_ref_head
, node
) {
1397 if (enabler_ref
->ref
->enabled
1398 && cds_list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
1399 has_enablers_without_bytecode
= 1;
1403 event
->has_enablers_without_bytecode
=
1404 has_enablers_without_bytecode
;
1406 /* Enable filters */
1407 cds_list_for_each_entry(runtime
,
1408 &event
->bytecode_runtime_head
, node
) {
1409 lttng_filter_sync_state(runtime
);
1415 * Apply enablers to session events, adding events to session if need
1416 * be. It is required after each modification applied to an active
1417 * session, and right before session "start".
1418 * "lazy" sync means we only sync if required.
1421 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
1423 /* We can skip if session is not active */
1424 if (!session
->active
)
1426 lttng_session_sync_enablers(session
);
1430 * Take the TLS "fault" in libuuid if dlopen'd, which can take the
1431 * dynamic linker mutex, outside of the UST lock, since the UST lock is
1432 * taken in constructors, which are called with dynamic linker mutex
1435 void lttng_fixup_event_tls(void)
1437 unsigned char uuid
[LTTNG_UST_UUID_STR_LEN
];
1439 (void) lttng_ust_uuid_generate(uuid
);